This is the most annoying little problem I get when I play on fields. For some reason everytime I show it to my local paintball dealer, it works flawlessly like nothing ever was wrong.  I shoot once and its fine... than when I shoot again, the paint ball just flops out of the barrel like a dead fish and the cock does not reset and remains in the (UNCOCKED) position. Than when you have to manually reset the thing (like a sniper rifle) it shoots like a monster as though the velocity knob was maxed and the gun shoots over 400 feet per second! And of course after this, you shoot again and it is (Uncocked again)     This is the most annoying problem of all. I tried adjusting the velocity screw (didn't work) I tried oiling the rear bolt (didn't work either) and I tried replacing the tank O-ring (still didn't work) 

    What the hell is wrong with my gun!

Its a 98 Custom,with standard Co2, and only upgrade I think could effect the gas is the end cap is replaced with a stock. As far as the valve screws...

Ehhhh I lost those two little guys. Thery were gone and not even screwed in the gun when I was getting these problems. I didn't think they were anything major, I forgot all about that they hold the valve in place. I would screw them in but they always would be in warped, maybe because the valve was off center in the power tube. As a result they fell out of the gun and I lost them on the field I was playing on. Maybe I'm gonna have to go pick some up.

Its both the valve screw holes and the right side marker holes that are worn. Almost like someone put a Screw 5 times fatter than what was supposed to be put in the holes... You see that is why you are NEVER supposed to order a gun from Actionvillage. You get screwed  corny I know

FireStrorm89 wrote: I just check with my local paintball dealer today and he had a spare set of valve screws. He plugged them in, they went in straight this time not warped like when I screwed them in. He shot the gun with a 20 Co2 tank and after the 5th shot the front valve screw shot out like a bullet and nearly almost hit me. He said that the right side receiver on the marker has worn out screw holes. WHAT! I used this gun like 4 times and 1 out of those times with the screws plugged in because I lost them after the first time I played. How did those screw holes get worn out?! Anyway I am going to send it to Tippmann and see if they can figure out why the valve screws keep shooting out when the gun is shot. Thats probably how I lost the screws the first time, they probably shot out of the gun when I was fighting and landed in the grass somewhere...

Loose screws would wear those holes out of round after only a few hundred shots. The stress on the screws, as the valve is being slammed back and forth by the hammer, work them in their threads  and wear out the threads VERY quickly...the screws are steel but the valve body is aluminum which is relatively soft.

Your marker may be under warranty. Send it to Tippmann. You also need to read up on your marker. You need to learn how to disassemble and reassemble your marker. You need to understand what each of those internal parts do and how to properly torque your screws. If the screws weren't important they wouldn't have been there in the first place. Tippmann makes a very simple and rugged marker that can take outrageous abuse. Your failure to familiarize yourself with your markers function obviously exceeded that "outrageous" level.